Improvement in furnaces for melting metals



1.H1uanlsfm.- Furnaces for Melting Metals.A

No. 141,139, Parentedlulyzznas..

AM. PHam-urflosmmrc ca. Mwmmfs mums) UNITED STATES PATENT OFFICE.

JAMES EAEEisON, OE EAST HAMPTON, CONNECTICUT.

IMPROVEMENT IN FURNACES FOR MELTING METALS.

Specification forming part of Letters Patent No. 141,139, dated July 22, 1873; application led February 20, 1873.

Ilo all whom it may concern Be it known that I, JAMES HARRISON, of East Hampton, in theA county of Middlesex, State of Connecticut, have invented Y a new and Improved Furnace for Melting Metals; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the annexed drawings making a part of this specification, in which- Figure 1 is a perspective section of the furnace, showing the furnace-bed A, the feeddoor' B, the space for the metallic breast or front C, the ash-pit D, the space for the ashpit door E, the grate-bar F, the fire-place G, the space for the fire-door H, and the funnelshaped arch I over the fire-place Gr. Fig. 2 is a front view, showing the ash-pit door E, the

lire-door H, and the blast-pipe connection J. Fig. 3 is a side view, showing the blast-pipe connection J and the draft-fines from the furnace to the chimney K K. Fig. 4 is an end view, showing the metallic breast or front C attached to the swing-crane L, and in its place in the furnace, also the half-funnelshaped metallic tapping-hole M, and the screw stay-bar n, and the two catches o o. Fig. 5 is afront view of the metallic breast or front C, detached from the swing-.crane L, showing the half-funnelshaped metallic tapping-hole M, the screw staybar u, and the center screw-bolt P. Fig. 6 is a side view of the metallic Vbreast or front C, showing the half-funnel-shaped metallic tapping-hole M, the center screw-bolt I), and the collar R, and spout q. Fig. 7 shows the ashpit D, the grate-bars F, the fire-place G, and the funnel-shaped arch I.

The sameletters are used to describe like parts, though given in diii'erent views. Y

The nature of my invention consists in the construction of the taper or. fun'nel shaped fireplace, and the construction of the movable metallic breast or front, in which is a half-funnel-shaped metallic tapping-hole, and the de-y vices necessary to operate the same, my object being to dispense with the use of crueibles in all Ordinary brass foundin gs.

To enable others skilled in the art to make and use my invention, I will now describe its construction and operation.

In constructing my furnace I use the same kind of material that is used in building hotair furnaces generally, namely, {ire-brick and lire-mortar. In Fig. l letter A represents the bed-pit of the furnace that holds the melted metal 5 letter B, the feed-door; letter (l, the recess in which the metallic breast or front is placed; letter D, the ash-pit, letter E, the ashpit door; letter F,the grate-bars; letter G, the Ere-place; letter H, the fire-door; letter Lathe fennel-shaped arch over the lire-place. Letters J, Figs. 2 and 3, are the blast-pipe connection. Letter K K, Fig. 3, are the fines that connect the furnace with the chimney. Letter L, Fig. 4, is the swing-crane that supports the metallic front when not in use in the furnace. Letter M is the half-funnel-shaped tapping-hole in the metallic front. Letter n is the screw stay-bar. Letters o o are the two catches that keep the stay-bar n in its place. Letter P is the center screw-bolt on which the stay-bar n works, and is kept in its place by the colla?.` R. Letter q is the spout that conveys the melted metal from the furnace to the vessel that is prepared to receive it.

By referring to Figs. land 7 it will be seen that the fire-place is much smaller at the firedoor than it is at the back, and that a gradual increase of width is maintained bothon the sides and in the arch over the top, thus making it funnel-shaped. By this means I find the draft is increased very much, and the heat, as fast as generated, is drawn into the larger Space that forms the furnace proper. I can melt more metal with less fuel, time, and labor than I have ever heard of being done before. The destruction of the reTplace by the ire is not so great in this furnace as in those where the funnel shape is not used.

In constructing the front of the furnace a hole is left about the middle of the front and a little below the bed ofthe furnace, as shown by letter C in Fig. 1. A breast-plate or front is then made to lit the hole thus left. This plate is made of metal or any suitable material. At the bottom of this plate or breast is a half-funnel-shaped tapping-hole, the larger circle being flush with the outside of the breast, and the small circle passing through the wall into the furnace. This will be understood by referring to Figs. 5 and 6 and to letters M. The screw-bolt l? is put through` the center ofthe breast and kept in its place by the collar It, and is made to work With ease. The stay-har n is put upon this bolt. By the side of this front is put up-a small swing-crane, L,from which a small chain is attached to the breast, for the purpose of sustaining and swinging the breast out of the way when not required. On cach side of the breast is a catch, 0 o; the recess of the one nearest the handle of stay-bar a is made on the Yupper side, and the recess in the other catchis made in the lower side, so as to allow the stay-bar to work in and out oi' the recesses, when required.

ln operating this furnace, I iirst coat the bottoln and sides of the furnace-bed A with a mixture of fire-clay and sand to fill up all the4 joints and cracks. I then put some of the same mixture on the' four sides of the breast-plate C, and then put it into the hole in the front of the furnace, and then put the staybar into the recesses in the catches o o, and, by turning the screw P to the left hand, force the breast into the hole until it makes a close fit, and the mixture of clay and sand put around the breast fills up the joints, and makes it tight. The stay-bar is left in this position until the cast is over, to prevent the breast-plate from being f'orced out by the pressure of the metal against it on the inside of the furnace. I then'put a little of the same sand and clay into the tapping-hole M to fill it up, and the furnace is ready for the fire. The tire is kindled in the lire-place. The blaze and smoke pass through the body of the furnace to the lines 7c lo; `then into the chimney. -The metal is put into the furnace at the feed-door B, and as the fiance passes over the metal it is melted, and it runs down to the lower part of the bed A, resting in part against the brick front, and in part against the breast-plate C. When there is a large quantity of metal to melt, and but little time to do it in, I can 'attach a blower or fan to the blast-pipe connection J, and close the ash-pit door E, and melt with the blast only but for a small lot of metal, and where the blast oan not be had, I open the ashpit door E and melt with air alone 5 so I can use this furnace either as a blast-furnace or an air-furnace, as circumstances may require. When the metal is ready to pour I take a small iron bar and make a small hole through the clay in the tappinghole M, and let as much metal run into the ladle as I desire, and then stop up the hole again with some ofthe sand-and-clay mixture. rlhis operation is repeated until all the metal is drawn out of the furnace.

It is sometimes the case that we have to tap out or draw metal from the furnace a hundred times before the cast is over, and it is in this respect that my furnace differs from ping-hole is as long as the brick wall is thickabout twelve inches, or nearly so--and is usually made of sand; and after tapping out the first time, and stopping up the hole, While We use the metal we have got, the metal that was in thelong tapping-hole when it was stopped up has set and become hard, and you cannot tap out again in the same place until the hard metal is forced backinto the furnace, and the hammering necessary to force it back will break away the sand made tapping hole, and all the metal that is in the furnace will run out. It is not so with my furnace. My tappinghole is made of metal, and is funnel-shaped,v

and at the nearest point to the melted metal is about one and a half inch, instead of twelve inches, and the clay-and-sand mixture can be forced into the tapping-hole thus far by the act of stopping up, thus making it impossible for the melted metal to get in and cool; consequently the operation of tapping out can be repeated all day, if necessary. When the metal is all drawn out of the furnace I turn the screw P to the right hand, while the stay-bar a remains in the catches o o, and by so doing I loosen and draw out the breast-plate C, and then, by relieving the stay-bar a from the catches o o, the crane L and the breast-plate G can be swung around to the side ofthe furnace, and out of the way. I then take an iron rake or hoe, and clean out all theslag from the furnace while it is in a molten condition. This saves the trouble of getting into the furnace when cold and chipping the slag oi' with a hammer ,and chisel, which is a very slow process.

What I claim as new, and desire to secure by Letters Patent, is-

l. The funnel-shaped metallic tapping-hole M with' the breast O, substantially as and for the purpose described.

2. The combination of the screw-bolt l?, collars R, and breast-plate C, substantially as described.

3. The combination of the breast-plate G with the stay-bar a and the screw-bolt P, substantially as described.

4. The combination of the swing-crane L with the breast-plate C, substantially as described.

5. rlhe taper hre-place G, with the funnelshaped arch I, in combination with a furnace, as and for the purpose specified.

JAMES HARRISON.'

Witnesses:

WILLIAM 1I. HARRISON, CLARA P. HARaisoN. 

